News / Science & Technology

Scientists Discover 1 Planet Orbiting 2 Stars

Artist's conception of planet (dark circle) orbiting two suns
Artist's conception of planet (dark circle) orbiting two suns

Astronomers say they have discovered a planet that orbits around a pair of stars.  It is the first time a so-called circumbinary system has been detected.

Movie fans might be familiar with the score of "Star Wars, Episode IV, A New Hope," the blockbuster movie from 1977.  Luke Skywalker stands on his stark home planet Tatooine.  As he gazes pensively into the distance toward a pinkish sky, an orange sun descends toward the horizon, with a smaller white sun following close behind.  

Well, move over, Tatooine, says John Knoll of Industrial Light and Magic, which created the special effects for the "Star Wars" films.

"Again and again we see that the science is stranger and cooler than the fiction," Knoll said.

Make way for reality -- Kepler-16b, the first planet known to definitively orbit two stars.  That makes it a circumbinary planet.

A research team, led by scientist Laurance Doyle, used data from the Kepler space telescope to make the discovery.

Kepler-16b is 200 light years from Earth.  It is about the mass of Saturn, and it is half-rock and half-gas.  It is in orbit around two stars that are smaller than our Sun, and those two stars are in what Doyle calls "an eccentric orbit" around each other.   

"Well, this is an example of another planetary system.  A completely different type that we've never seen before.  And so that's why everybody is making a big deal of it.  Nobody's ever seen a place like this before. . . with one exception.  I seem to remember seeing a place like this about 30 years ago in a galaxy far, far away...," Doyle said.

And that would, of course, be the "Star Wars" fictional planet Tatooine.  

Researchers describe this newly discovered Kepler system as a rather graceful one.  The two stars twirl around each other every 41 days.  The planet orbits in a circle around both of the stars every 229 days.

But how did researchers find it?

The Kepler space telescope measures changes in the brightness of more than 150,000 stars as it searches for transiting planets.  
All three bodies in this system orbit in the same plane, and that is why the telescope observed the various planetary and stellar eclipses.  The dimming in brightness at irregular intervals indicated the stars were in different positions in their orbit each time they were passed by the third body, planet Kepler-16b.

"We have two stars dancing around each other, and in our line of sight, they eclipse each other, and then we have this exquisite little pirouette of the planet going around both of them, and we get to see how big the planet is as well," Doyle said.

Scientists were able to deduce the planet's mass by the gravitational tug on the stars, as measured by changes in their eclipse times.

The goal of the Kepler mission is to find other Earth-like planets that could support life.  Doyle says this planet is not habitable.

"The bright star is kind of orange.  It's more orange than the sun.  And the little star is red.  It's very red.  So that's an example of another thing to be considered when you talk about habitable planets is, 'what is the color of the light?'  Is it color that plants can use to photosynthesize, and so on?," Doyle said.

Doyle says researchers do not yet know the rotation period, so they do not yet know the planet's sunrises and sunsets.  But, he said, they would be dynamic because of the stars' eccentric orbits.  Sometimes the red star would set first, sometimes the orange one.  Sometimes they would set together.  

"You'd have, of course, two shadows, because the orange star would cast a shadow, but the red star would fill it in because it's at a different angular point in the sky, and vice versa.  So, if you want to tell the time by sundial, you'd need calculus, you know," Doyle said.

The findings are described in a study published in the September 16th issue of the journal Science.

You May Like

UN Fears Rights Violations in China-backed Projects

UNHCHR investigates link between financing development and ignoring safeguards for human rights More

Boko Haram Violence Tests Nigerians’ Faith in Buhari

New president has promised to stem insurgency; he’s scheduled to meet with President Obama at White House July 20 More

Social Media Network Wants Privacy in User’s Hands

Encryption's popularity in messaging is exploding; now it's the foundation of a new social network More

This forum has been closed.
Comments
     
There are no comments in this forum. Be first and add one

Featured Videos

Your JavaScript is turned off or you have an old version of Adobe's Flash Player. Get the latest Flash player.
Making Music, Fleeing Bombs: New Film on Sudan’s Internal Refugeesi
X
Carolyn Weaver
July 06, 2015 6:47 PM
In 2012, Sudanese filmmaker Hajooj Kuka went to make a documentary among civil war refugees in Sudan’s Blue Nile and Nuba Mountains region. What he found surprised him: music was helping to save people from bombing raids by their own government. VOA’s Carolyn Weaver has more.
Video

Video Making Music, Fleeing Bombs: New Film on Sudan’s Internal Refugees

In 2012, Sudanese filmmaker Hajooj Kuka went to make a documentary among civil war refugees in Sudan’s Blue Nile and Nuba Mountains region. What he found surprised him: music was helping to save people from bombing raids by their own government. VOA’s Carolyn Weaver has more.
Video

Video Rice Farmers Frustrated As Drought Grips Thailand

A severe drought in Thailand is limiting the growing season of the country’s important rice crop. Farmers are blaming the government for not doing more to protect a key export. Steve Sandford reports from Chiang Mai, Thailand.
Video

Video 'From This Day Forward' Reveals Difficult Journey of Transgender Parent

In her documentary, "From This Day Forward", filmmaker Sharon Shattuck reveals the personal journey of her transgender father, as he told his family that he always felt he was a woman inside and decided to live as one. VOA’s Penelope Poulou has more.
Video

Video Floodwaters Threaten Iconic American Home

The Farnsworth House in the Midwest State of Illinois is one of the most iconic homes in America. Thousands of tourists visit the site every year. Its location near a river inspired the design of the house, but, as VOA’s Kane Farabaugh reports, that very location is now threatening the existence of this National Historic Landmark.
Video

Video Olympics Construction Scars Sacred Korean Mountain

Environmentalists in South Korea are protesting a Winter Olympics construction project to build a ski slope through a 500-year-old protected forest. Brian Padden reports that although there is strong national support for hosting the 2018 Pyeongchang Winter Olympics, there are growing public concerns over the costs and possible ecological damage at the revered mountain.
Video

Video Xenophobia Victims in South Africa Flee Violence, Then Return

Many Malawians fled South Africa early this year after xenophobic attacks on African immigrants. But many quickly found life was no better at home and have returned to South Africa – often illegally and without jobs, and facing the tough task of having to start over. Lameck Masina and Anita Powell file from Johannesburg.
Video

Video Family of American Marine Calls for Release From Iranian Prison

As the crowd of journalists covering the Iran talks swells, so too do the opportunities for media coverage.  Hoping to catch the attention of high-level diplomats, the family of American-Iranian marine Amir Hekmati is in Vienna, pleading for his release from an Iranian prison after nearly 4 years.  VOA’s Heather Murdock reports from Vienna.
Video

Video UK Holds Terror Drill as MPs Mull Tunisia Response

After pledging a tough response to last Friday’s terror attack in Tunisia, which came just days before the 10th anniversary of the bomb attacks on London’s transport network, British security services are shifting their focus to overseas counter-terror operations. VOA's Henry Ridgwell has more.
Video

Video Obama on Cuba: This is What Change Looks Like

President Barack Obama says the United States will soon reopen its embassy in Cuba for the first time since 1961, ending a half-century of isolation. VOA White House correspondent Luis Ramirez reports.
Video

Video Hate Groups Spread Influence Via Internet

Hate groups of various kinds are using the Internet for propaganda and recruitment, and a Jewish human rights organization that monitors these groups, the Simon Wiesenthal Center, says their influence is growing. The messages are different, but the calls to hatred or violence are similar. VOA's Mike O’Sullivan reports.
Video

Video Blind Somali Journalist Defies Odds in Mogadishu

Despite improving security in the last few years, Somalia remains one of the most dangerous countries to be a journalist – even more so for someone who cannot see. Abdulaziz Billow has the story of journalist Abdifatah Hassan Kalgacal, who has been reporting from the Somali capital for the last decade despite being blind.
Video

Video Rabbi Hits Road to Heal Jewish-Muslim Relations in France

France is on high alert after last week's terrorist attack near the city Lyon, just six months after deadly Paris shootings. The attack have added new tensions to relations between French Jews and Muslims. France’s Jewish and Muslim communities also share a common heritage, though, and as far as one French rabbi is concerned, they are destined to be friends. From the Paris suburb of La Courneuve, Lisa Bryant reports about Rabbi Michel Serfaty and his friendship bus.

VOA Blogs